[deliverable/linux.git] / arch / ppc64 / kernel / idle.c

/*
 * Idle daemon for PowerPC.  Idle daemon will handle any action
 * that needs to be taken when the system becomes idle.
 *
 * Originally Written by Cort Dougan (cort@cs.nmt.edu)
 *
 * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
 *
 * Additional shared processor, SMT, and firmware support
 *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/sysctl.h>

#include <asm/system.h>
#include <asm/processor.h>
#include <asm/cputable.h>
#include <asm/time.h>
#include <asm/systemcfg.h>
#include <asm/machdep.h>
#include <asm/smp.h>

extern void power4_idle(void);

void default_idle(void)
{
	long oldval;
	unsigned int cpu = smp_processor_id();

	while (1) {
		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);

		if (!oldval) {
			set_thread_flag(TIF_POLLING_NRFLAG);

			while (!need_resched() && !cpu_is_offline(cpu)) {
				ppc64_runlatch_off();

				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();
			}

			HMT_medium();
			clear_thread_flag(TIF_POLLING_NRFLAG);
		} else {
			set_need_resched();
		}

		ppc64_runlatch_on();
		schedule();
		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
	}
}

void native_idle(void)
{
	while (1) {
		ppc64_runlatch_off();

		if (!need_resched())
			power4_idle();

		if (need_resched()) {
			ppc64_runlatch_on();
			schedule();
		}

		if (cpu_is_offline(smp_processor_id()) &&
		    system_state == SYSTEM_RUNNING)
			cpu_die();
	}
}

void cpu_idle(void)
{
	BUG_ON(NULL == ppc_md.idle_loop);
	ppc_md.idle_loop();
}

int powersave_nap;

#ifdef CONFIG_SYSCTL
/*
 * Register the sysctl to set/clear powersave_nap.
 */
static ctl_table powersave_nap_ctl_table[]={
	{
		.ctl_name	= KERN_PPC_POWERSAVE_NAP,
		.procname	= "powersave-nap",
		.data		= &powersave_nap,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{ 0, },
};
static ctl_table powersave_nap_sysctl_root[] = {
	{ 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
 	{ 0,},
};

static int __init
register_powersave_nap_sysctl(void)
{
	register_sysctl_table(powersave_nap_sysctl_root, 0);

	return 0;
}
__initcall(register_powersave_nap_sysctl);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Idle daemon for PowerPC. Idle daemon will handle any action
	3	* that needs to be taken when the system becomes idle.
	4	*
	5	* Originally Written by Cort Dougan (cort@cs.nmt.edu)
	6	*
	7	* iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
	8	*
	9	* Additional shared processor, SMT, and firmware support
	10	* Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*/
	17
	18	#include <linux/config.h>
	19	#include <linux/sched.h>
	20	#include <linux/kernel.h>
	21	#include <linux/smp.h>
	22	#include <linux/cpu.h>
1da177e4	23	#include <linux/sysctl.h>
1da177e4 LT	24
	25	#include <asm/system.h>
	26	#include <asm/processor.h>
1da177e4 LT	27	#include <asm/cputable.h>
1da177e4 LT	28	#include <asm/time.h>
1da177e4	29	#include <asm/systemcfg.h>
fd899c0c	30	#include <asm/machdep.h>
2249ca9d	31	#include <asm/smp.h>
1da177e4 LT	32
	33	extern void power4_idle(void);
	34
143a1dec	35	void default_idle(void)
1da177e4 LT	36	{
	37	long oldval;
	38	unsigned int cpu = smp_processor_id();
	39
	40	while (1) {
	41	oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
	42
	43	if (!oldval) {
	44	set_thread_flag(TIF_POLLING_NRFLAG);
	45
	46	while (!need_resched() && !cpu_is_offline(cpu)) {
45e75dfb AB	47	ppc64_runlatch_off();
45e75dfb AB	48
1da177e4 LT	49	/*
	50	* Go into low thread priority and possibly
	51	* low power mode.
	52	*/
	53	HMT_low();
	54	HMT_very_low();
	55	}
	56
	57	HMT_medium();
	58	clear_thread_flag(TIF_POLLING_NRFLAG);
	59	} else {
	60	set_need_resched();
	61	}
	62
45e75dfb	63	ppc64_runlatch_on();
1da177e4 LT	64	schedule();
	65	if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
	66	cpu_die();
	67	}
1da177e4 LT	68	}
1da177e4 LT	69
143a1dec	70	void native_idle(void)
1da177e4	71	{
45e75dfb AB	72	while (1) {
	73	ppc64_runlatch_off();
	74
1da177e4 LT	75	if (!need_resched())
1da177e4 LT	76	power4_idle();
45e75dfb AB	77
	78	if (need_resched()) {
	79	ppc64_runlatch_on();
1da177e4	80	schedule();
45e75dfb	81	}
1da177e4	82
45e75dfb	83	if (cpu_is_offline(smp_processor_id()) &&
1da177e4 LT	84	system_state == SYSTEM_RUNNING)
	85	cpu_die();
	86	}
1da177e4 LT	87	}
1da177e4 LT	88
1da177e4 LT	89	void cpu_idle(void)
1da177e4 LT	90	{
fd899c0c ME	91	BUG_ON(NULL == ppc_md.idle_loop);
fd899c0c ME	92	ppc_md.idle_loop();
1da177e4 LT	93	}
	94
	95	int powersave_nap;
	96
	97	#ifdef CONFIG_SYSCTL
	98	/*
	99	* Register the sysctl to set/clear powersave_nap.
	100	*/
	101	static ctl_table powersave_nap_ctl_table[]={
	102	{
	103	.ctl_name = KERN_PPC_POWERSAVE_NAP,
	104	.procname = "powersave-nap",
	105	.data = &powersave_nap,
	106	.maxlen = sizeof(int),
	107	.mode = 0644,
	108	.proc_handler = &proc_dointvec,
	109	},
	110	{ 0, },
	111	};
	112	static ctl_table powersave_nap_sysctl_root[] = {
	113	{ 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
	114	{ 0,},
	115	};
	116
	117	static int __init
	118	register_powersave_nap_sysctl(void)
	119	{
	120	register_sysctl_table(powersave_nap_sysctl_root, 0);
	121
	122	return 0;
	123	}
	124	__initcall(register_powersave_nap_sysctl);
	125	#endif